Systems and methods use ion exchange to extract lithium from a lithium-containing feed solution such as a salar brine. Lithium ions are loaded into an ion exchange resin and then eluted while recharging the resin. Sodium hydroxide or sodium bicarbonate may be used to recharge the resin but are not directly mixed with the lithium-containing feed solution. An eluate stream is produced containing lithium hydroxide or lithium bicarbonate. Lithium hydroxide can be precipitated as lithium hydroxide or in a hydrate form. Lithium bicarbonate may be converted to lithium carbonate. The system and method optionally includes processing an eluate stream to recover one or more compounds for re-use in regenerating the resin bed.

A system and method configured to restore ion exchange kinetic properties and purify resin is described. Degraded ion exchange kinetic properties of anion resin will eventually result in impurity slippage through resin charges. This system and method employs an acid catalyst in combination with sulfite cleaning solution to remove organic material and to protonate iron oxides for deconstruction and removal from anion resins. The cleaning solution, when applied via a cleaning vessel utilizing an eductor(s)/plenum and wedge-wire screen draw chamber, while controlling all phases of cleaning by electronic monitoring, yields complete restoration of ion exchange kinetics on usable resin. As such, the system and method provides a safe, effective, and vastly improved method for restoring anion resin kinetics and improving regeneration quality, for improved resin performance and minimizing resin replacement costs.

A system and method configured to restore ion exchange kinetic properties and purify resin is described. Degraded ion exchange kinetic properties of anion resin will eventually result in impurity slippage through resin charges. This system and method employs an acid catalyst in combination with sulfite cleaning solution to remove organic material and to protonate iron oxides for deconstruction and removal from anion resins. The cleaning solution, when applied via a cleaning vessel utilizing an eductor(s)/plenum and wedge-wire screen draw chamber, while controlling all phases of cleaning by electronic monitoring, yields complete restoration of ion exchange kinetics on usable resin. As such, the system and method provides a safe, effective, and vastly improved method for restoring anion resin kinetics and improving regeneration quality, for improved resin performance and minimizing resin replacement costs.

Methods and apparatus for removing contaminants from liquid using a continuously circulating stream of purifying media are disclosed. In one embodiment the method includes mixing a regenerated purifying media with a contaminated liquid containing diverse contaminants; co-currently transporting the purifying media and the contaminated liquid in a mixed state; removing, using the purifying media, while co-currently transporting the purifying media and the contaminated liquid, contaminants from the contaminated liquid so as to produce a mixture of a decontaminated liquid and a contaminated purifying media; and separating contaminated purifying media from the decontaminated liquid. In addition, the contaminated purifying media is contacted in counter current fashion with a regenerant solution so as to produce a regenerated purifying media and the regenerated purifying media is returned to the mixing step, whereby the continuously circulating purifying media selectively removes contaminants from the liquid.

Provided herein is a process of ion exchange comprising malonic acid or a salt thereof and a cation or an anion cation exchange resin. The ion exchange is accomplished, e.g., and without limitation by continuous ion exchange. A valve and resin bed configuration is useful in this regard. The malonic acid separated by ion exchange is esterified, e.g., by Fisher esterification by using an acid and an alcohol.